Feeding problems !!

[kidvett]

Hello,

I just finished building a nice 6 inch shooter pistol ( rust blue, strawed parts, new barrel ) and did some test firing. I used 2 good magazines ( one current MecGar & one SE63 ) that are working in other pistols. Ammo is 124gr FMC. Here is the problem: rounds are caught upwards halfway in the chamber in an oblique angle ( bullet pointing top ) on the feeding cycle...Dummy rounds dont do it, only live ones when firing...

Throat on bottom edge of barrel has both top & botton edges sharp. I thought that polishing & smooting those 2 angles could cure the problem...

What do you think...

Thanks for the help,

Mark <img border="0" title="" alt="[Wink]" src="wink.gif" />

[Thor]

First thing I check with feeding problems is magazine spring strength, then I also check to make sure the round is powerful enough to lock back the breech block. Make sure you have a STRONG spring.

[John Sabato]

THOR's right Mark... test the ammo by single loading one round with an empty magazine seated properly and see if it will consistently lock back the toggle with the holdopen. If it does that we have halfway home. That would indicate that the ammo is powerful enough to work the action.

Now... about those sharp edges... are you saying that the lower edge of the mouth of the chamber where the round must slide in order to leave the magazine and feed properly is a sharp edge? That should be smoothly radiused so there is no sharp edge. I know the radius requirement for this edge appears on the blueprints, but I am isolated from my print drawings for a week or so...

If you decide to polish this area, do it VERY lightly over a cylindrical form like a wooden dowel approximately the size of the 9mm cartridge... Just literally take the "edge" off by rounding it ever so slightly...Lugers should NOT be ramp polished as you might do on a 1911 Colt...

Since you say it is a custom barrel, it is likely that the barrelsmith (you?) left the chamber edge too sharp and it is catching the cartridge case while loading. Is there any evidence of the cartridges being "galled" by the sharp edge?

[Thor]

I shot a Luger last week and it WAS marking the top of the bullet with two scratch/gouges from the top of the chamber, the feed lips were too open and they had been moved enough times they wouldnt stay in one place, I switched magazines and the problem went away.

[kidvett]

Thor & John,

Thanks for the hints I tried it with Win 147gr SXTs and it would work 5 times out of 8 with a strong 2 hands hold...I discarded the MecGar mag following Thor's advice as it's spring seems too weak for this gun. SE63 mag worked...but I'll try it with FXO's as they have a stronger spring. The gun is more reliable with 147gr that CCI 124gr's. Powerfull ammo needed ??

John,

The Gunsmith installed the barrel & left that sharp edge on the lower mouth...I'll try to polish it a little like you recommended...

It seems funny as I have a well used 5 in 30 Cal favorite shooter that has weaker springs ( everyone of'em right to the mainspring ! ) but functions with even that MecGar mag !! and is reliable `` most `` of the time...Should we be considering 9mm Lugers `` Big Bores `` in the family ?? Stiffer springs needed with the 9mm ??

Note: I only have those kind of reliability problems with `` built shooter pistols `` as most Collector Grade pistols I shot ( forbidden ?? ) never gave problems...wherever Military or Commercial guns...

I'll get back with results from the next shooting session...

Many thanks for the hints & advices...

Regards,

MARK

[Thor]

YIKES! <img border="0" title="" alt="[Eek!]" src="eek.gif" /> Dont discard the magazine, just put in a stronger spring from Wolff!

[LugerLizzie]

Where can you get the Wolff springs? Are they readily avaialble at a gun store locally? Or are they special order?

[John Sabato]

Here ya go!

http://www.gunsprings.com/SemiAuto/LugerNF.html

[Thor]

MAKE SURE you check the shape of your magazine spring. Some of the Wolff springs are ZIGZAG or RECTANGULAR and some are the round coil spring. These are 10% over power so GET A LOADING TOOL. Your thumb will thank you! <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" />

[unspellable]

Be aware that any factory load in 9 mm Parabellum available today has an OAL that is shorter than the original DWM minimum OAL. (SAAMI maximum length is the orginal DWM minimum length. Any factory load I know of is shorter than the SAAMI maximum.) This is the cause of many magazine feeding problems. The Luger magazine works like a 22 LR magazine in that the bullet point must ride up on the front of the magazine at the correct angle. There should be no contact between the edge of one case mouth and the next while they are in the magazine.

Just because it says 9 mm Luger on the end flap doesn't mean it's really Luger ammo.

[Vlim]

Hi,

Interesting subject that inspired me to do some checking:

I have compared a present-day Sellier and Bellot 9mm 115gr FMJ with a 1917 DWM-made round.

Case length: 19.05 MM
Tip length: 10.95 MM
Total length:30 MM

Weight and dimensions are a perfect match. Not strange, since S&B was one of the 9mm suppliers in the luger-days, using the LKM production code.

A 1940 winchester drawing of the 9mm shell shows:
Case length: 0.754" = 19.1516 MM
Total length: 1.169" = 29.6926 MM

Both cases are well over 19MM long, a clear indication of their reliability in lugers. Lengths of over 19.17 MM generally are too much. Everything between 19.00MM and 19.17MM should feed and extract properly.



I would be interested in the exact sizes of 115gr 9mm walmart winchester to see if the present day versions are still the same size as the 1940 ones.

[unspellable]

Vlimmeren,

The SAAMI maximum OAL is 1.169 inch. Your 1917 DWM round and S&B round appear to be just a tad over that. So far as I know all US loaded ammo is under 1.169 inch. I've had a computer crash and lost most of my drawings, but the DWM minimum was right around 1.169 inch.

The really criitical point is where the ogive rests on the front magazine wall. This point is not at the exact center of the point so does not correlate exactly with the overall length. In any case, the nose is meant to ride up the front of the magazine as opposed to a stack magazine where the nose may not even touch the magazine wall.

I suspect that some after market magazines may be slightly shorter front to back to accomodate today's shorter cartridge. This may also apply to some or all of the stainless Luger magazines.

I'd appreciate any drawings you or anyone else might send me of cartrdiges, chambers, bores, or recoil springs.

[Vlim]

Hi,

'The Dutch Luger' has some drawings (with sizes) of both early DWM 9mm cartridges and the 1940 Winchester 9mm drawing.

Hope this helps,

I'm still interested in some comparative measurements of 'fresh' Winchester 9mm, to see if they fit the SAAMI max or that they are more in line with DWM specs.

One trick I learned quite quicly is to let the bullets 'ride' the magazine a few times after loading by pulling up and down on the follower knob. Of course this works good with a max of 5 cartrigdes. When filled to the max it's not very easy to do.

[kidvett]

Hello,

Second try with the pistol...got it to function with an FXO mag...broke one ejector...Ammo used was SXTs 147grs & 124gr FMCs...

I will try to get some mesurements of the SXT ammo. I placed an order for some springs from Wolff...

Curious as to recoil that seems harsher from this 6 inch gun than 4 inch Military pistols ??

Also, 5 inch 30 Cal Shooter that works with soft springs mags that do not work in the 9mm 6 in. gun ??

Mark

[policeluger]

6 inch vs 4inch and why harsher?...you are holding the bullet in the barrel almost 50% longer, I know the bullet is accelerating as it goes, but the longer the bullet stays traveling down the barrel, the more pressure is being built up due to more powder burning in the chamber/barrel, and hotter burning, then in a short barrel.....and 30 cal vs 9mm. two different powder charges, burning rates and again barrels

[Doubs]

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by kidvett:
<strong>Also, 5 inch 30 Cal Shooter that works with soft springs mags that do not work in the 9mm 6 in. gun ?? Mark </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">There's likely a different recoil impulse between the two cartridges. Also, the bottle-neck .30 cartridge is, IMO - and in my experience - a more reliable cartridge in the Luger. It feeds more reliably because it IS a bottle-neck and enters the chamber with much more room around it than the larger 9mm. IOW, think of a flat-faced, sharp-shouldered pin going into a close-tolerance hole vs a beveled-shoulder pin. Pretty much the same principle.

[Thor]

Well put Doubs!

[unspellable]

The 9 mm has a greater impulse than the 7.65, but not by much. Going from a 4 inch to a six inch barrel will result in slightly greater velocity and hence slightly greater impulse but this is off set by the heavier barrel and tends to cancel.

In practice, subjective differences in felt recoil are often much greater than objective measured differences. And often in the opposite direction.

I have a Winchester M1984 in 32 Special that kicks rather severely due to a poorly designed stock. I have a William Evans 400-360 that by any objective measured standard recoils much more than the Winchester but feels like less because it has a well designed stock. It throws a bullet of almost twice the weight of the 32 Special.

[kidvett]

Hello,

Specifications for the Winchester ammo used in the test fire of the 6 in shooter Luger:

147 gr Subsonic Match ( X9MMTCM ):
Cartridge OAL: 1.116 in
Case lenght: 0.749 in

124gr BEB Win Clean ( XC92 ):
Cartridge OAL: 1.115 in
Case lenght: 0.749 in

147gr SXT ( RA9T ):
Cartridge OAL: 1.116 in
Case lenght: 0.749 in



I'm sorry if my questionning may seems basic to some...I'm no expert, never claimed to be...just a small LE guy...My understanding is that this forum is for sharing information...So I ask what I'm unsure of...and respect answers from people with a lot more knowledge than me, wherever it is by profession, experience and/or long time collecting...

My experience is that FELT recoil has always been greater with longer barreled pistols...P99QA or G19 pistols dont kik compared to that 6 in Luger. 4 in Mdl 29 flips less that same gun in 6.5 in...same for 45LC 25-5...

Mark

[Johnny C. Kitchens]

The best ammo I've been able to use in my byf42, is no longer made, but it is Winchester with a 95gr. JSP. It's OAL = 1.065. I used this stuff in two different byf42, and they both were having trouble with other ammo. If you saw the video of my gun firing eight shots without a problem, that is the ammo I'm using. I'm almost out and I'm hoping to find a replacement. I didn't realize that it was no longer available till just recently. I bought enough to last when I discovered how well it worked. I've been reading these length recommendations and it makes me wonder. I even have an article that recommends 1.170 to 1.180 OAL. My thought on why these work, is their light weight and nice taper down to a small flat point makes it chamber better. I'm hoping to find another bullet with this profile to test. Just might be the magic bullet...